Rotors for a permanent magnet rotary electric machine include, for example, a rotor of a surface permanent magnet (SPM) rotary electric machine in which multiple permanent magnets are fixed to a surface of a rotor shaft by press-fitting retaining rings.
For example, Patent Literature 1 listed below discloses a rotor for a permanent magnet rotary electric machine which includes multiple permanent magnets fixed to an outer surface of a rotor shaft and a tubular carbon fiber reinforced plastic ring (hereafter, referred to as CFRP ring) fitted to outer surfaces of the multiple permanent magnets. In this rotor, an interference is provided between the inner diameter of the CFRP ring and the outer diameter of the permanent magnets and the multiple permanent magnets are firmly fixed to the rotor shaft by press-fitting the CFRP ring.
Patent Literature 2 discloses a permanent magnet rotor including multiple permanent magnets bonded to a center portion of a rotor hub and multiple retaining rings fitted to outer surfaces of the multiple permanent magnets. The multiple permanent magnets are machined such that a tapered surface continuous from one axial end side to another axial end side of the rotor hub is formed on the outer peripheral surfaces of the permanent magnets as a whole. The retaining rings are each press-fitted while being provided with a predetermined interference to the outer peripheral surface of the corresponding permanent magnet.